In manufacturing of electronic devices, e.g., batteries, fuel cells, etc., component design often involves various pieces being assembled together by welding, e.g., two or more thin metal sheets.
Typically, such thin metal sheets are positioned together and placed on a welding support. A welding device (e.g., CO2 high energy laser, electron beam/plasma, arc-welder, and/or other similar devices) can then be used to perform a welding operation.
To obtain an effective and complete weld, it is helpful to ensure that the proximal edges of the objects (e.g., thin metal sheets) to be joined are positioned and immobilized during the welding operation. Such immobilization is often accomplished by way of mechanical clamps, the clamps being anchored to fixtures external to the welding support on which the metal sheets have been placed.
The use of mechanical clamps during welding, however, leads to inefficiencies in work-piece production. In particular, mechanical clamping mechanisms require increased time to clamp and unclamp the sheets in position prior to and after welding. A further disadvantage of conventional apparatus is that the increased clamping time resulting from the use of mechanical clamps inhibits adjustment in the positioning of the sheets which are to be welded together once the clamps are engaged.
Magnetic clamping devices have been introduced in an attempt to overcome the deficiencies of the available clamping means. For example, WO97/26110 describes an apparatus for positioning, clamping and welding together proximal edge portions of two sheet blanks. An electromagnet and ferromagnetic clamping shoes act together to hold the two sheets in place such that the edges of the sheets may be butt welded with a laser.
Korean patent application KR100826469 describes a clamping apparatus for laser welding overlapping steel sheets. An electromagnet is configured to act on hydraulically or pneumatically operated clamps to retain a bottom steel sheet and a top steel sheet by way of the magnetic force created by the electromagnet.
British patent GB1438023 describes a system for welding a flange to a pipe, pneumatic actuators controlling a position of the electromagnet so as to retain the flange to be welded.
Xiao M, Bradley P., “Robotic Nd: YAG” Laser welding system and its applications, Aerospace Congress and Exhibition (ACE 2003), describes a laser welding system for welding non-magnetic materials, the system having an electro-magnetic base and equipped with different fixtures for positioning parts. Magnetic clamping shoes are used to clamp the parts based on the magnetic force generated by the electro-magnetic base.
The inefficiencies of the above systems are apparent when trying to perform full peripheral/circumferential laser welds on clamped parts which have optical obstructions due to the clamps and/or support structures related to the clamps.
Moreover, the prior art lacks an effective and efficient system for positioning and removing clamps from the parts being clamped in an electromagnetic clamping system such that repetitive placement and clamping can be performed easily and accurately.
It is accordingly a primary object of the disclosure to provide systems and methods for molding that overcome the deficiencies of the currently available systems and methods.